In Defense of IQ Testing: Lewis M. Terman Replies to Critics

“There is nothing about an individual as important as his IQ,” declared psychologist Lewis M. Terman in 1922. To the extent that this is true, it is in large measure because of Terman himself and the opportunity that World War I afforded for the first widespread use of intelligence testing. The army’s use of intelligence tests lent new credibility to the emerging profession of psychology, even as it sparked public debate about the validity of the tests and their implications for American democracy. The idea that experts could confidently assign a man to his proper place in the army—and by extension, his place in life—suggested a kind of determinism that some found profoundly at odds with American democracy and its credo of upward mobility through hard work. In “The Great Conspiracy,” Lewis Terman replied with acid commentary to a series of articles by Walter Lippmann criticizing IQ tests. Terman portrayed Lippmann as a sentimental humanist whose democratic dogma prevented him from accepting plain facts. According to Terman, Americans clearly exhibited a range of different intellectual endowments and the new science of psychology made it possible to measure and classify those differences.

After Mr. [William Jennings] Bryan had confounded the evolutionists, and . . . the astronomers, it was only fitting that some equally fearless knight should stride forth in righteous wrath and annihilate that other group of pseudo-scientists known as “intelligence testers.” Mr. Walter Lippmann, alone and unaided, has performed just this service. That it took six rambling articles to do the job is unimportant. It is done. The world is deeply in debt to Mr. Lippmann. So are the psychologists, if they only knew it, for henceforth they should know better than to waste their lives monkeying with those silly little “puzzles” or juggling IQ’s and mental ages.

What have intelligence testers done that they should merit such a fate? Well, what have they not done? They have enunciated, ex cathedra, in the guise of act, law and eternal verity, such highly revolutionary and absurd doctrines as the following; to wit:

(1) That the strictly average representative of the genus homo is not a particularly intellectual animal;

(2) that some members of the species are much stupider than others;

(3) that school prodigies are usually brighter than school laggards;

(4) that college professors are more intelligent than janitors, architects than hod-carriers, railroad presidents than switch-tenders; and (most heinous of all)

(5) that the offspring of socially, economically and professionally successful parents have better mental endowment, on the average, than the offspring of said janitors, hod-carriers and switch-tenders.

These are indeed dangerous doctrines, subversive of American democracy. The crime of the “intelligence testers” is made worse by the fact that they have attempted to gain credence for their nefarious theories by resort to cunningly devised statistical formulae which common people do not understand. It is true that some of these doctrines had been voiced before, but as long as they were expressed in ordinary language they passed as mere opinion and did little harm. But to talk about mental differences in terms of IQ’s, or to reckon mental inheritance in terms of a “.50 coefficient of resemblance between parent and offspring,” is a far more serious matter. In the interest of freedom of opinion there ought to be a law passed forbidding the encroachment of quantitative methods upon those fields which from time immemorial have been reserved for the play of sentiment and opinion. For example, why should not one be allowed to take his political or social theory as he takes his religion, without having it all mixed up with IQ’s, probable errors and coefficients of correlation?

At any rate, it will not do to let the idea get abroad that human beings differ in any such vital trait as ability to think, comprehend, reason; or, if such difference really exist, that there is the remotest possibility of anyone ever being able to measure them. If the psychologists should succeed in getting the intelligentsia to swallow this vanity-satisfying doctrine, who knows what they would not next succeed in putting over a system of plural voting based upon intelligence indices (to be determined by these self-same psychologists)? Absurd? By no means. Suppose, for example, they should somehow manage to give a test to the members of Congress (it should be done without their knowing it) and should then shrewdly award to each and every one a flatteringly high IQ. Sheer instinct on the part of the recipients could be depended upon to do the rest.

Let there be no misapprehension; the principle of democracy is at stake. The essential thing about a democracy is not equality of opportunity, as some foolish persons think, but equality of mental endowment. Where would our American democracy be if it should turn out that people differ in intelligence as they do in height; especially if the psychologists could make it appear that he had discovered a method of triangulating everybody’s intellectual altitude? The argument of the psychologists that they would use their method in the discover and conservation of talent, among rich and poor alike, is brazen camouflage. They don’t care a twirl-o'-your-thumb about the conservation of talent. Their real purpose is to set up a neoaristocracy, more snobbish, more tyrannical and on every count more hateful than any that has yet burdened the earth. Insomuch as the psychologists know their little “puzzle” stunts better than anyone else can hope to know them, they are doubtless entertaining ambitious visions of themselves forming the cap stone of this new political and social structure. As Mr. Lippmann well says, “if the tester could make good his claim that his tests test intelligence he would soon occupy a position of power which no intellectual has held since the collapse of theocracy.” In short, the whole thing is motivated by the Nietzschean Impulse Imperious.

It is high time that we were penetrating the wiles of this crafty cult. We have been entirely too unsuspecting. For example, the innocent-minded Germans are being shamefully taken in at this very moment. Hardly had the old government of Germany crashed, when the educational authorities of the newly established republic allowed the psychologists to launch a wild orgy of intelligence testing in the schools. The orgy continues unabated. The ostensible purpose is to sift the schools for superior talent in order to give it a chance to make the most of itself, in whatever stratum of society it may be found. The psychologists pretend that they are trying to break up the old Prussian caste system. They are not. It is the Impulse Imperious. If the German people don’t wake up they will soon find themselves in the grip of a super-junker caste that will out-junker anything Prussia ever turned loose. England and the other European countries are in similar danger. The conspiracy has even spread to Australia, South Africa and Japan. It is world-wide.

Now it is evident that Mr. Lippmann has been seeing red; also, that seeing red is not very conducive to seeing clearly. The impassioned tone of these six articles gives their case away. Clearly, something has hit the bulls-eye of one of Mr. Lippmann’s emotional complexes. From the concentration of attack upon me one would infer that I had caused all the trouble, even to the point of seducing an eminent psychologist as William McDougall. If such is the case, my responsibility is very great, for a majority of the psychologists of America, England and Germany are now enrolled in the ranks of the “intelligence testers,” and all but a handful of the rest use their results.

The six articles are introduced by the editors of the New Republic as a critical “analysis and estimate of intelligence tests.” As it turns out; the estimate is considerably more in evidence than the analysis. The former rings out clearly in every paragraph; the latter, when it is not downright loco, is vague and misleading. One gathers, however, that Mr. Lippmann thinks he has a mission to perform and that the end justifies the means. This is not an accusation; it is a charitable way of explaining his misuse of facts and quotations.

The validity of intelligence tests is hardly a question the psychologist would care to debate with Mr. Lippmann; nor is there any reason to engage in so profitless a venture. It is only necessary to examine casually a few samples of his allegations in order to show what weight they should carry.1

Sample No. 1. The belief that our draftees in the war had an average mental age of only fourteen years rests entirely upon the mental age standards embodied in the Stanford Revision of the Binet test. These standards were based upon a mere handful of samplings and are entirely overthrown by the army results. The army tests have “knocked the Stanford Revision into a cocked hat.”

As a matter of fact, the belief in question does not rest at all upon the correctness of the Stanford mental age norms. Independent age norms have several times been derived for the army tests by applying them to large groups of unselected school children. I have presented some of these norms in the very report from which Mr. Lippmann quotes a few of the facts he is unable to interpret.2 Such independently derived norms for the Alpha test, for the Beta test and for the Yerkes-Bridges Point Scale (all used in the army), agree with the Stanford-Binet in the verdict as to average mental age of our drafted soldiers. On every kind of test that was employed, even the most non-verbal, the average scored earned by draftees was less than that earned by average fourteen-year-old school children. Psychologists are not entirely agreed as to how this fact should be interpreted, but that is beside the point. Those who accept the army data at their face value think that the “Fourteen-Year” tests of the Stanford-Binet should be renamed “Average Adult” tests. The possible desirability of such renaming has no bearing whatever on the average mental age of soldiers or, for that matter, on the validity of the Stanford tests as a measure of intelligence.

Sample No. 2. The intelligence rating earned by a soldier was determined chiefly by the time limits used in giving the tests.

The effects of increased time limits were thoroughly investigated by the Division of Psychology, Surgeon General’s Office. The results of the experiment, which was carried out under my direction by Dr. Mark A. May, are stated in the following words: “In general, then, we have no reason to assume that an extension of time limits would have improved the test or have given an opportunity to many individuals materially to alter their ratings.”3 In fact, scores earned by 510 men on regular time correlated with scores earned by the same group on double time to the extent of .965. This means, of course, that the top five percent by one method included almost exactly the same men as were in the top five percent by the other method, and similarly for a cross section in any range of the score distribution. These facts are to be found just three pages from a statement which Mr. Lippmann takes out of its setting and quotes in a manner certain to mislead.

Sample No. 3. The symmetrical distribution of IQ’s resulting from application of the Stanford-Binet to unselected children is no proof whatever of the validity of the test.

Perfectly true and perfectly irrelevant. I have never made such a claim, although Mr. Lippmann tries to give the impression that I have. It is true, as he asserts, that coin-tossing gives an even more symmetrical curve of distribution. Mr. Lippmann uses this illustration in order to suggest that intelligence score distributions, like those for coin-tossing, are mainly a product of chance. (He does admit they are “not quite as chancy as that.”) What are the facts? Over and over again the experiment has been made of testing a large group of children twice, with an interval of several days, or months, or even years between the tests. Each pupil’s original score is then paired with his later score, and a correlation coefficient is computed for the two series of tests. If the scores were due to chance, the resulting correlations would of course be .00. Actually they are nearly always above .80, and occasionally above .90. If Mr. Lippmann will make two one-thousand series of coin-tosses and then correlate the results of the two series by pairing first toss with first toss, second toss with second toss, etc., he will get, not .80 or .90, but .00, plus or minus a small probable error.

Sample No. 4. The tests are doubtless useful in classifying school children, but this is no evidence that they test intelligence.

Possibly it is not; or possibly it depends upon one’s definition of intelligence. Most of us have uncritically taken it for granted that children who attend school eight or ten years without passing the fourth grade or surmounting long division, are probably stupider than children who lead their classes into high school at twelve years and into college at sixteen. Mr. Lippmann contends that we can’t tell anything about how intelligent either one of these children is until he has lived out his life. Therefore, for a lifetime at least, Mr. Lippmann considers his position impregnable!

Sample No. 5. Although intelligence tests are capable of rendering valuable service in classifying school children, they are in great danger of becoming an “engine of cruelty” by being turned into “a method of stamping a permanent sense of inferiority upon the soul of the child.” Nothing could be more contemptible than to—etc., etc.

Mr. Lippmann does not charge that the tests have been thus abused, but that they easily could be. Very true; but they simply aren’t. That is one of the recognized rules of the game. Isn’t it funny what horrible possibilities an excited brain can conjure up? I recall a patient who had worked himself into a wretched stew from thinking how terrible it would be if butchers by concerted action all over the country, should suddenly take it into their heads to slaughter their unsuspecting customers. He was actually determined to get a law passed that would deprive these potential murderers of their edged and pointed tools.

Sample No. 6. There is no proof that mental traits are inherited. Goddard thought he had proved it for mental deficiency, but Cattell questions his evidence. Galton thought he had proved it for genius, but Cattell doesn’t seem to think much of that proof either.

Note how cleverly Mr. Lippmanmn strives for effect by playing off one psychologist against another. He resorts to this frequently. The trick is very simple; all you do is to take an isolated statement out of its original setting and quote it in a setting made to order. In that way you can have an expert opinion on your side. Mr. Bryan is said to use this method with telling effect against the evolutionists. Not that psychologists don’t sometimes disagree, even as doctors do. It would be a sorry outlook for their young science if they did not. But when the outsider comes along and tries to make capital out of such differences, it is well to be on one’s guard. In ninety-nine cases out of a hundred it means that an unfair advantage is being taken both of the reader and the author quoted. Think, for example, of Mr. Lippmann’s quoting Cattell in support of his tirade against intelligence testing—Cattell, the pupil of Galton, the father of mentality testing in America, the inventor of new methods for the study of individual differences, the author of important studies (in progress) on the inheritance of genius!

Sample No. 7. (Main Allegation, asserted at least three times in every paragraph, always with signs of greatly increased blood pressure.) The intelligence tests don’t test pure intelligence. Any appearance to the contrary is due to “a subtle statistical illusion.” The psychologist’s assumption “that his questions and puzzles can in fifty minutes isolate abstract intelligence is vanity.” It is worse than vanity; it is an attempt to restore the “doctrine of predestination and infant damnation” in favor of an “intellectual caste system,” etc., etc.

It is evident that Jack has prepared an imposing giant for the slaughter. No matter that it is stuffed with straw or that it is set up in a fashion to make it the easy victim of a few vigorous puffs of super-heated atmosphere. As a matter of fact, all the “intelligence testers” will readily agree with Mr. Lippmann that their tests do not measure simon pure intelligence, but always native ability plus other things, with no final verdict yet as to exactly how much the other things affect the score. However, nearly all the psychologists believe that native ability counts very heavily. Mr. Lippmann doesn’t. He prefers to believe that more probably an individual’s IQ is determined by what happens to him in the nursery before the age of four years, in connection with the “creative opportunities which the parents and nurse girls improved or missed or bungled”! After all, if our experiences in the nursery gave us our emotional complexes, as the Freudians say, why shouldn’t they have determined our IQ’s at the same time?

One wonders why Mr. Lippmann, holding this belief, did not suggest that we let up on higher education and pour our millions into kindergartens and nurseries. For, really and truly, high IQ’s are not to be sneezed at. The difference between 150 IQ and 50 IQ is the difference between an individual who will be able, if he half tries, to graduate from college with Phi Beta Kappa honors at twenty, and an individual who at that age can hardly do long division, make change for four cents out of twenty-five or name the months of the year. Even the difference between 100 IQ and 75 IQ is the difference between the ability to graduate from high school or possibly from college, and inability to do even first year of high school work satisfactorily.

And just to think that we have been allowing all sorts of mysterious, uncontrolled, chance influences in the nursery to mould children’s IQ’s, this way and that way, right before our eyes. It is high time that we were investigating the IQ effects of different kinds of baby-talk, different versions of Mother Goose, and different makes of pacifiers and safety pins. If there is any possibility of identifying, weight and bringing under control these IQ stimulants and depressors, we can well afford to throw up every other kind of scientific research until the job is accomplished. That problem once solved, the rest of the mysteries of the universe would fall easy prey before our made-to-order IQ’s of 180 or 200.

Does not Mr. Lippmann owe it to the world to abandon his role of critic and to enter this enchanting field of research? He may safely be assured that if he unravels the secret of turning low IQ’s into high ones, or even into moderately higher ones, his fame and fortune are made. If he could guarantee to raise certified 100’s to certified 140’s, or even certified 80’s to certified 100’s, nothing but premature death or the discover and publication of his secret would keep him out of the Rockefeller-Ford class if he cared to achieve it. I know of a certain modern Croesus who alone would probably be willing to start him off with ten or twenty million if he could only raise one particular little girl from about 60 to 70 to a paltry 100 or so. Of course, if this man had only understood the secrets of “creative opportunity” in the nursery, he might have had all this and more for nothing. Who knows but if the matter were put up to him in the right way he would be willing to endow for Mr. Lippmann a Bureau of Nursery Research for the Enhancement of the IQ?

If Mr. Lippmann gets this Bureau started there are several questions I shall want to submit to it for solution. Some of these have been bothering me for a long time. One is, why both high and low IQ’s are so often found in children of the same family and of the same nursery. To be sure, parental habits change more or less as children come and grow up; nurse girls arrive and depart; toys wear out. The problem admittedly is complex, but by successive experiments in which one factor after another is kept constant while the others were varied, the evil and beneficent influences might gradually be sorted out.

Next, I should want to propose a minute comparative study of the influences operative in our California Japanese nurseries and those of our California Portuguese. Here is mystery enough to challenge any group of scientists Mr. Lippmann can get together, notwithstanding the apparent similarity of nursery environment in the two cases, the IQ results are markedly different. Our average Portuguese child carries through school and into life an IQ of about 80; the average Japanese child soon develops an IQ not far below that of the average California white child of Nordic descent. In this case the nurse girl factor is eliminated; one might almost say, the nursery itself. But of course there are the toys, which are more or less different. It is also conceivable that the more liquid Latin tongue exerts a sedative effect on infants' minds as compared with the harsher Japanese language, which may be stimulating in comparison.

Another problem would relate to the IQ resemblance of identical twins as compared with that of fraternal twins. The latest and most extensive investigation of this problem4 indicates a considerably greater IQ resemblance for the former than for the latter. This is a real poser; which I leave to Mr. Lippmann without attempting an explanation.

Notes:

1 His allegations are here stated in highly condensed form, as the text is much to verbose for literal quotation.

2 Psychological Examining in the United States Army. Vol. 15, National Academy of Science Memoirs, p. 536 ff.